Total Internal Reflection test block

thingiverse

I designed this straightforward test block to verify and confirm complete internal reflection in a clear print. For my resin print, it should be coated with a layer of resin after printing, drip-dried, then cured to produce a glassy finish. Faces for testing: -The semicircle at the bottom allows radial light to strike the circle's center (on the vertical flat surface) at any angle and test for the critical angle. -Viewing from the vertical flat side, one can observe bright reflections from the semicircular surface. The slanted flat surface can be used as a mirror, reflecting light normal to the bottom out from the vertical flat surface and vice versa. -Viewing straight into the slanted flat surface, the bottom and vertical surface act as the mirror and would reflect light normal and into the slanted surface back out. Background: Initially I noticed that post processing of clear resin prints can bring out a glass-like finish and upon observing complete internal reflection in one such print, I decided that I must check the critical angle of my resin and am eager to test what I can potentially achieve with this discovery